Lemon Batteries: Lighting an LED With Lemons





Introduction: Lemon Batteries: Lighting an LED With Lemons

Did you know you can light an LED using fruits and vegetables?

For this experiment, you will need the following materials:

  • 4 lemons or potatoes
  • 4 galvanized nails
  • 4 U. S. copper pennies (minted before 1982 due to the change in copper content) or 4 copper wires
  • an LED light
  • a knife
  • 5 alligator test leads

Step 1: Creating the Batteries

  1. Using the knife, slice a penny-sized slit on the right side of your lemon.
  2. Push the penny far into the lemon, leaving a small area to hook your alligator jumper to. This will be your positive terminal.
  3. Now, create the negative terminal for your battery. Stick one of the galvanized nails into the left side of the lemon, about 2 inches away from the penny. It is important to have the nail and penny separated. If they touch, it will cause a short.
  4. Repeat this process until you have 4 complete batteries.

Step 2: Adding the Jumpers

  1. Make sure the lemons are aligned parallel to one another.
  2. Attach one of the alligator clips to the nail (negative terminal) on your first lemon.
  3. Then, run the second jumper wire from the penny (positive terminal) of the first lemon to the nail (negative terminal) in the second lemon. Add the rest of the clips, alternating positive an negative, until all the lemons are attached.

Step 3: Lighting the LED

  1. Connect the first jumper wire from the nail to the negative connection on the LED. The negative connection on the LED is the shorter wire nearest the base.
  2. Then, clip the jumper wire from the penny of the last lemon in your chain to the positive connection on the LED. When you complete your circuit, the LED will light up!
  3. Experiment with different fruits and vegetables to see which one produce the most volts! The higher the voltage, the brighter the light. The average lemon produces just under 1 volt. We need at least 3.5 volts to light up an LED. This is why we need 4 lemon batteries.

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20 Discussions

why must u torture your lemons

but your lemons look like Frankenstein

This will be a great STEM activity with kids, thanks!


2 years ago

Any idea how many amps 1 lemon can produce with a nail and penny? I imagine it will depend on surface area.

2 replies

Also the distance between nail and penny

It says at the end... "The average lemon produces just under 1 volt. We need at least 3.5 volts to light up an LED. This is why we need 4 lemon batteries." But doesn't mention Amps anywhere.

Can I eat the lemons or potatoes after I am done using them as batteries?

1 reply

How long will it power the LED for?


2 years ago

It's important the nails are galvanized. Non-galvanized nails will not work. "Galvanized" means that the nails are covered with a protective layer of zinc.


2 years ago

A bit of an old trick, but the LED gives it a modern twist.You could light up your gin and tonic, then use the leftovers, but maybe not, health and safety. UK sneakily devalued the copper coinage so it's now copper-plated steel - only use is as washers.

Also use a Potato (or Potatoe).

educational purposes should connect only two rooms and two nails and remove one of the two, measuring each time the power connection and then continue by adding lemons but by measuring each time made the extra energy. A good way to test more connected in series or in parallel of two series of lemons.

dans un but éducatif il faudrait connecter seulment deux pièces et deux clous puis enlever l'un des deux, mesurer à chaque fois la puissance et continuer ensuite le branchement en rajoutant des citrons mais en mesurant à chaque fois l'énergie supplémentaire apportée. Un bon moyen en plus de tester branchement en série ou en parallèle de deux séries de citrons.

Awesome! This is always a great science fair project. Thanks for sharing the detailed steps. Very nicely done!

1 reply

when i first saw a guy using a patato and powerade to charge a phone i thought that was fake.

then whoooaaaaaahhhhhhh